Treadle switch



Oct. 2, 1934. LE oy H ZElGER 1,975,527

TREADLE SWITCH Filed Aug. 29, 1932 2 Sheets-Sheet l Oct. 2, 1934. LE ROY H. ZEIGER TREADLE SWITCH Filed Aug. 29, 1952 2 Sheets-Sheet 2 Patented Oct. 2, 3.934

UNHTEE SFATES earner or ies This invention relates to signals for controlling traffic upon highways and is intended for use at intersecting highways in localities where the traffic is suiilciently heavy to require a controlling signal but conditions do not warrant the installation of an intricate, entirely automatic signaling system. The present invention provides a signal which will be controlled or operated by a vehicle traveling along one of two intersectin roads,

m the passage of the vehicle operating trip devices which will set the signal to give the vehicle a clear road at a distance from the intersecting road and will then reset the signal after the vehicle crosses the intersecting road so that travel upon the other road will be free to pass and will be interrupted only when necessary to permit travel upon the intersecting road and avoid congestion. llhe invention is illustrated in the accompanying drawings and will be hereinafter fully described,

I m the novel features being particularly pointed out in the appended claim.

In the drawings, Fig. l is a perspective view of a highway crossing showing my improved signal installed thereat,

$5 Fig. 2 is an enlarged View through one of the trip boxes showing the box in longitudinal vertical section,

Fig. 3 is a section on the line 33 of Fig. 12,

Fig. 4 is a view similar to Fig. 2 but showing a 30 section through another of the boxes employed,

Fig. 5 is a plan view of the apparatus shown in Fig. 4,

Fig. 6 is an enlarged detail section on the line 6-6 of Fig. 51,

Fig. 7 is a diagrammatic view showing the electrical circuits employed for controlling the signal.

In the drawings, the reference numeral 1 indicates a. road which is crossed by another road 2 and at the intersection of which are erected posts 3 upon which are mounted signal lamps, indicated at i. As best seen in Fig. 1, the posts 3 are mounted at points on opposite sides of the intersection and diagonally thereof. In the roadbeds of each of the roads, and at a distance from the intersection to be determined by the allowed speed of traflic, there are provided trip boxes 5 which are set in the ground at the side of the road with their tops flush with the roadbeds, a

'50 typical box being shown more clearly in Figs. 2

and 3 of the drawings, and to be hereinafter described. Extending laterally from the top of the box is a plate 6 which is set in the roadbed at the right hand side of the same and which is of a suiiicient width to be always in the path of the wheels of a vehicle traveling over the road toward the intersection. The plate 6 is provided, between its ends, with a transverse groove or depression 7 which constitutes a seat for a rock shaft 8 provided upon its upper side with a longitudinal rib 9 which will project above the surfaces of the plate and of the roadbed a sufficient distance to be moved by theimpact of the wheels of an oncoming vehicle but will not project above the surface to such an extent as to 5 jar the vehicle and thereby render riding uncomfortable nor to present a dangerous obstruction to pedestrians. It will be understood, upon reference to Fig. 2, that when the wheel of a vehicle strikes the rib 9 in its travel toward the intersection, the rib will be shifted with the travel of the vehicle and the rock shaft 8 will be rocked accordingly. At the end of the shaft 8 and depending therefrom within the box 5 is a crank arm 10 which may be formed integral with the shaft or rigidly secured thereto, as may be preferred, and to the end of this crank arm is at tached a retractile spring 11 which has its opposite end anchored upon the wall of the box so that the crank arm and the shaft are normally held in such position as to present the rib 9 toward the oncoming vehicle, as shown in Fig. 2.

A stop lug 12 is provided on the side wall of the box and projects in front of the crank arm, as shown in Figs. 2 and 3, so that the movement of the arm under the influence of the retractile spring will be limited and the arm and the rib will, consequently, be always in proper operative position. Mounted within the box, upon a bracket 13, are two resilient plates 14 and 15 which constitute electric terminals and are provided at their ends with contact points 16 whereby if the plates be pressed together an electric circuit will be closed through them. These terminal plates are insulated from the supporting bracket 13 and to the fixed ends thereof are attached the ends of conductors 17 which extend, respectively, to

a source of electric energy and to the lamps 4 whereby, as best seen in Fig. '7 of the drawings, when the circuit is closed, the proper signal will be displayed to permit the vehicle to cross the intersection. The crank arm 10 bears upon the upper terminal 14, as shown in Fig. 2, and the end of the arm may be equipped with a pad of suitable form, indicated at 18, to avoid marring of the terminal and also to prevent short circuit- 05 ing between the terminal and the crank arm, it being understood that the pad will be of some insulating material.

Immediately adjacent the intersection there are provided second boxes 19 from the side of which, at the top thereof, plates 20 extend onto and are -seated fiush in the roadbed. A typical box is shown in detail in Figs. 4 and 5 of the drawings. The plate 20 is provided between its ends with a transverse seat 21 for a rock shaft 22 which is provided with a rib 23, the shaft and the rib corresponding in all essential respects to the shaft 8 and rib 9. A crank arm 24 is carried by an end of the shaft 22 and depends therefrom within the box 19, the forward movement of this crank e 'n being limited by a stop lug 25 correspondin to the stop lug 12 and the end of the crank arm being equipped with a pad 26 of insulation. A retractile spring 27 holds the crank arm normally in the position shown in Fig. 4. Secured within the box 19 is a bracket 28 to which contact terminals 29 and 30 are secured and insulated therefrom. These contacts 29, 30 are constructed of resilient metal and the lower contact member 30 extends beyond the end of the contact 29 and bears against the pad 26 on the crank arm 24, as shown. It will also be noted that the "id of the contact 29 is turned downwardly so as to extend at a right angle to the contact terminal 30 and bear against the same, Conductors 31 are attached to the fixed ends of the terminals 29 and 30 and extend, respectively, to the signal lamps and to the source ofelectric energy.

When the apparatus is properly installed at a crossing, the boxes 5 and 19 will, of course, be disposed on each road at opposite sides of the intersection in pairs so that the signal may be operated by a vehicle traveling in either direction upon either road. The terminals 14 and 15 are normally separated, and when a vehicle rocks the shaft 8, the crank arm 10 will be swung downwardly and rearwardly so that the upper terminal 14 will be pressed against the terminal 15 to close a circuit for energizing the field coil of a relay 32 which will instantaneously attract an armature 33. As the armature 33 swings toward the attracting pole of the core of the relay, it closes contacts 34 which retain the circuit closed through the relay 32, which circuit would otherwise be broken by the removal of pressure from the terminals 14 and 15. The armature 33 also closes contacts 35 which are electrically connected to a field coil of a double acting master relay, which is indicated in general by the numeral 36, through a set of contacts 36. The master relay 36 is provided with a pivoted armature 37 having a contact-engaging cross piece 38 at one end thereof. When the field coil of the master relay is energized, the armature 37 will be rocked uponits pivot and the contactvengaging cross piece 38 will close a set of contacts 39, normally associated in close proximity thereto, which are electrically connected with a set of lights 40 in the posts 3. When a vehicle has arrived at the intersection a wheel thereof will cross the plate 20 of the box 19 and will rock the shaft 22 and will open the terminals 29 and 30 which are electrically connected in series with the field coil of the first relay, which opening of the terminals 29 and 30 will break the circuit and permit the contacts 34 and 35 to open, thereby allowing the armature of the master relay to be released and thereby breaking the circuits to the lights 40. The lights 40 will, of course, be

colored, or will be located behind colored lenses so that they will emit a green colored light through the lens in the direction of the oncoming vehicle and will emit a red light through a second lens in the direction of a vehicle approaching on the other road.

A vehicle approaching on the other road would cross over like boxes 6 and 19 disposed in the roadbed adjacent the intersection and would energize relays in the same manner as hereinbefore described.

It is to be understood, of course, that the master relay will be provided with a second field coil and a second set of contacts so that when said second field coil is energized by the closing of contacts on the second road, said second set of contacts will be actuated by the rocking of the armature to close a circuit through said contacts to lights which will indicate a green signal for the oncoming vehicle on said second road, and a red signal for a vehicle approaching the intersection upon the road first described.

It is to be further understood that a separate relay is employed for each set of trip boxes. That is, there will be four relays and a master relay. The relays operated by trip boxes on the same road at opposite sides of the intersection will be connected in parallel and either will operate one section of the master relay, the other section of said master relay being operable by the other two relays on the other road which are likewise connected in parallel.

Attention is directed to the fact that, inasmuch as there are signal posts at each side of the intersection diagonally thereof, a driver approaching the intersection on either road will experience little or no difliculty in seeing the signal lights.

It will be seen that I have provided a simple and highly efiicient traffic controlling signal which will not easily get out of order and which will be durable and require little or no attention after installation.

Having thus described the invention, I claim:

In a crossing signal, a box, a plate extending laterally from the box and set in a road and having' a groove in its upper surface transverse to the road a pair of resilient terminals within the box, a rock shaft seated in said transverse groove to be actuated by a passing vehicle on the road and having a longitudinal rib normally presented to the vehicle, a crank arm depending from said rock shaft within the box and bearing upon one of said terminals, yieldable means for holding the crank arm in normal position, and a stop in the box extending into the path of the crank arm to limit he movement of the crank arm under the influence of said means.

LE ROY H. ZEIGER. [r..s.l 

